BeagleBoard XM C2, Reference Manual

Page: 101 / 163

REF: BB_SRM_xM
BeagleBoard-xM System
Reference Manual
Revision C2
Page 101 of 163
Figure 47. Camera Modules
At this time, only the VGA camera board has been confirmed to work on the –xM board.
Other boards will be added as the SW drivers are completed. The 3MP module is next on
the list. It is expected that all of the listed modules will work and no complications are
expected as they are all compatible at the hardware level.
7.21 RS232 Port
A single RS232 port is provided on the BeagleBoard and provides access to the TX and
RX lines of
UART3 on the processor. Figure 48 shows the design of the RS232 port.
U9
SN65C3221EPW
EN
1
C1+
2
C1-
4
C2+
5
C2-
6
RIN
8
G
N
D
14
VC
C
15
FORCEOFF
16
V+
3
V-
7
ROUT
9
DOUT
13
INVALID
10
FORCEON
12
DIN
11
232_C1-
RS232_RX1
R79 0,DNI
R78 0
C147 0.1uF,10V
R80 0,DNI
RS232_TX1
R82 0
R81 10K
VIO_1V8
C143
0.1uF,10V
232_V-
232_V+
C151
0.1uF,10V
C149
0.1uF,10V
C148
0.1uF,10V
C150
0.1uF,10V
UART3_TX_3V
232_C2-
UART3_RX_3V
P8
DSUB_FEMALE_SHORT
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
SHL1
10
SHL2
11
232OE
232_PIN3
U10
TXS0102DCU
A1
5
B1
8
VCCA
3
VCCB
7
OE
6
GND
2
A2
4
B2
1
C146 0.1uF,10V
AUX_3V3
UART3_RX 3
AUX_3V3
UART3_TX 3
232_PIN2
Figure 48. RS232 Interface Design
7.21.1 Processor Interface
Two lines,
UART3_Tx and UART3_Rx , are provided by the processor. The UART3
function contains a programmable baud generator and a set of fixed dividers that divide
the 48-MHz clock input down to the expected baud rate and also supports auto bauding.
7.21.2 Level Translator